UINT16 MEMCALL
cpu_codefetch_w(UINT32 offset)
{
const int ucrw = CPU_PAGE_READ_CODE | CPU_STAT_USER_MODE;
descriptor_t *sdp;
UINT32 addr;
sdp = &CPU_CS_DESC;
addr = sdp->u.seg.segbase + offset;
if (!CPU_STAT_PM)
return cpu_memoryread_w(addr);
if (offset <= sdp->u.seg.limit - 1)
return cpu_lmemoryread_w(addr, ucrw);
EXCEPTION(GP_EXCEPTION, 0);
return 0; /* compiler happy */
}
void CPUCALL
interrupt(int num, int intrtype, int errorp, int error_code)
{
descriptor_t gsd;
UINT idt_idx;
UINT32 new_ip;
UINT16 new_cs;
int exc_errcode;
VERBOSE(("interrupt: num = 0x%02x, intrtype = %s, errorp = %s, error_code = %08x", num, (intrtype == INTR_TYPE_EXTINTR) ? "external" : (intrtype == INTR_TYPE_EXCEPTION ? "exception" : "softint"), errorp ? "on" : "off", error_code));
if(num == 0x21 && md_int21()) {
return;
}
CPU_SET_PREV_ESP();
if (!CPU_STAT_PM) {
/* real mode */
CPU_WORKCLOCK(20);
idt_idx = num * 4;
if (idt_idx + 3 > CPU_IDTR_LIMIT) {
VERBOSE(("interrupt: real-mode IDTR limit check failure (idx = 0x%04x, limit = 0x%08x", idt_idx, CPU_IDTR_LIMIT));
EXCEPTION(GP_EXCEPTION, idt_idx + 2);
}
if ((intrtype == INTR_TYPE_EXTINTR) && CPU_STAT_HLT) {
VERBOSE(("interrupt: reset HTL in real mode"));
CPU_EIP++;
CPU_STAT_HLT = 0;
}
REGPUSH0(REAL_FLAGREG);
REGPUSH0(CPU_CS);
REGPUSH0(CPU_IP);
CPU_EFLAG &= ~(T_FLAG | I_FLAG | AC_FLAG | RF_FLAG);
CPU_TRAP = 0;
new_ip = cpu_memoryread_w(CPU_IDTR_BASE + idt_idx);
new_cs = cpu_memoryread_w(CPU_IDTR_BASE + idt_idx + 2);
LOAD_SEGREG(CPU_CS_INDEX, new_cs);
CPU_EIP = new_ip;
} else {
/* protected mode */
CPU_WORKCLOCK(200);
VERBOSE(("interrupt: -------------------------------------------------------------- start"));
VERBOSE(("interrupt: old EIP = %04x:%08x, ESP = %04x:%08x", CPU_CS, CPU_EIP, CPU_SS, CPU_ESP));
#if defined(DEBUG)
if (num == 0x80) {
/* Linux, FreeBSD, NetBSD, OpenBSD system call */
VERBOSE(("interrupt: syscall# = %d\n%s", CPU_EAX, cpu_reg2str()));
}
#endif
idt_idx = num * 8;
exc_errcode = idt_idx + 2;
if (intrtype == INTR_TYPE_EXTINTR)
exc_errcode++;
if (idt_idx + 7 > CPU_IDTR_LIMIT) {
VERBOSE(("interrupt: IDTR limit check failure (idx = 0x%04x, limit = 0x%08x", idt_idx, CPU_IDTR_LIMIT));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
/* load a gate descriptor from interrupt descriptor table */
memset(&gsd, 0, sizeof(gsd));
load_descriptor(&gsd, CPU_IDTR_BASE + idt_idx);
if (!SEG_IS_VALID(&gsd)) {
VERBOSE(("interrupt: gate descripter is invalid."));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
if (!SEG_IS_SYSTEM(&gsd)) {
VERBOSE(("interrupt: gate descriptor is not system segment."));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
switch (gsd.type) {
case CPU_SYSDESC_TYPE_TASK:
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_16:
case CPU_SYSDESC_TYPE_TRAP_32:
break;
default:
VERBOSE(("interrupt: invalid gate type (%d)", gsd.type));
EXCEPTION(GP_EXCEPTION, exc_errcode);
break;
}
/* 5.10.1.1. 例外／割り込みハンドラ・プロシージャの保護 */
if ((intrtype == INTR_TYPE_SOFTINTR) && (gsd.dpl < CPU_STAT_CPL)) {
VERBOSE(("interrupt: intrtype(softint) && DPL(%d) < CPL(%d)", gsd.dpl, CPU_STAT_CPL));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
if (!SEG_IS_PRESENT(&gsd)) {
VERBOSE(("interrupt: gate descriptor is not present."));
EXCEPTION(NP_EXCEPTION, exc_errcode);
}
if ((intrtype == INTR_TYPE_EXTINTR) && CPU_STAT_HLT) {
VERBOSE(("interrupt: reset HTL in protected mode"));
CPU_EIP++;
CPU_STAT_HLT = 0;
}
switch (gsd.type) {
case CPU_SYSDESC_TYPE_TASK:
interrupt_task_gate(&gsd, intrtype, errorp, error_code);
break;
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_16:
case CPU_SYSDESC_TYPE_TRAP_32:
interrupt_intr_or_trap(&gsd, intrtype, errorp, error_code);
break;
default:
EXCEPTION(GP_EXCEPTION, exc_errcode);
break;
}
VERBOSE(("interrupt: ---------------------------------------------------------------- end"));
}
CPU_CLEAR_PREV_ESP();
}
